It found evidence that a single blast from a typical IED can
cause traumatic brain injury (TBI) and chronic traumatic
encephalopathy (CTE).

CTE is a progressive degenerative disease of the
brain found
in athletes and others with a history of repetitive
brain trauma that leads to brain tissue death. Like TBI, which is
considered to be its precursor, CTE results in psychiatric
symptoms (e.g. personality changes,
depression) and long-term cognitive disability
(e.g. memory loss, impaired judgment, dementia).

The team of researchers — which included eminent CTE expert
Dr. Ann McKee as well as leading experts in blast
physics, experimental pathology and neurophysiology —
investigated the brains of four military personnel with known
blast exposure and compared them to brain tissue samples
from four athletes who had a history of repetitive
concussive injury and four comparably-aged people with
no history of concussions or neurological disease.

The investigators found that the signs of CTE in the military
veterans resembled those in the athletes and were consistent
with brain samples from
other athletes examined by McKee at the Center for
the Study of Traumatic Encephalopathy in
Massachusetts.

When examining the effects of a single blast exposure, they found
that long-term impairments in brain functions were
observed in mice just two weeks after exposure to a single
blast.

In a press release, researchers estimated that TBI may affect
20 percent of the 2.3 million servicemen and women deployed
since 2001.

"Our laboratory experiments show that blast exposure
can produce both structural and functional damage that may be
long-lasting and is likely to underlie the profound cognitive,
memory, and perhaps mood and post-traumatic stress disorders,
experienced by many soldiers," said [Dr.
Patrick] Stanton, who is director of the Neural
Systems Laboratory at [New York Medical College].

Researchers found that the blast wind from an IED — at a velocity
of up to 330 miles per hour — as opposed to the shock wave leads
to TBI and CTE, but immobilizing the head during blast exposure
in mice prevented the learning and memory deficits associated
with CTE.

Nevertheless, making sure the skull doesn't shake is easier said
than done.

Dr. Lee Goldstein, associate professor at Boston
University School of Medicine,stated
that the results were encouraging to efforts concerned with the
diagnosis and rehabilitation of traumatic brain injuries:

"Our study provides compelling evidence that blast
TBI and CTE are structural brain disorders that can emerge as a
result of brain injury on the battlefield or playing
field," Goldberg said. "Now that we have identified the
mechanism responsible for CTE, we can work on developing ways to
prevent it so that we can protect athletes and our military
service personnel."